1. Field of the Invention
The invention relates to a suture sleeve for one or two implantable leads, the suture sleeve being adapted to be inserted into a vein to secure and protect the lead from damage when a suture thread is positioned and tied around the vein in the region over the suture sleeve to prevent bleeding from the vein, of the type having two lead receiving through holes, into each of which a medical implantable lead is insertable.
The invention also relates to a method for implanting one or two leads into a vein.
2. Description of the Prior Art
It is sometimes desirable to implant an electrical lead into a vein in an animal or human body, such that the lead extends out from the vein. This is the case e.g. when implanting a pacemaker into a body for monitoring and controlling the heart function. The pacemaker itself is implanted just under the skin in a pacemaker pocket at a suitable position, whereas one or more leads are inserted through an opening in the wall of a vein and pushed in until a distal end enters the heart where it can be attached to the heart wall.
However, the vein must be closed after lead insertion to avoid bleeding and the lead must be fixated in relation to the vein to eliminate the risk that the lead accidentally can be drawn out from its position. Avoiding bleeding is very important to prevent local hematoma since hematoma is considered as a major positive predictor for infection in the pacemaker pocket. This is accomplished by means of a suture thread, which is positioned around the vein and the lead in the area of the cut opening in the wall of the vein and which is tied around the vein and the lead. However, when closing the vein by tying the suture around the vein and the lead, there is a risk that the lead might get damaged by squeezing of the suture thread around the lead if the suture is made too tight. The suture stress will be concentrated to a small area and may cause intensive abrasion load to the lead body. On the other hand, if the suture is not tight enough, bleeding may occur and cause hematoma. If the suture is not combined with fixation of the lead elsewhere, there is also a risk for longitudinal lead movement and lead dislodgment if the suture is not sufficient tight.
To eliminate these risks it is known to use a so called suture sleeve, which is positioned around the lead in the area of the lead-through in the wall of the vein. In this way the suture sleeve will protect the lead from damage by the suture thread and the suture sleeve will fixate the lead in a sufficient degree.
However, sometimes it is desirable to connect the pacemaker with the heart by means of two separate leads. In such a case it is common practice to tying the suture around the vein directly onto unprotected leads to prevent from bleeding. The leads are then fixated separately some distance from the vein entrance by using the suture sleeves to prevent from longitudinal lead movement and lead dislodgement. This has effect that the leads in the venous entrance, where they are unprotected from the suture thread, may become damaged.
U.S. Pat. No. 5,107,856 discloses a suture sleeve for two leads. The suture sleeve is formed as a flexible strip having two spaced apart lead receiving channels. During use, one lead is positioned in each of the lead receiving channels and then the flexible strip is wrapped around the leads. Finally, the suture sleeve is positioned in the cut opening in the vein and tied around by a suture thread.
However, there are several disadvantages with such a suture sleeve. For example, it is not possible to position and fixate only one lead in a suture sleeve, which is adapted for two leads, since then blood will leak out through the channel which has no lead positioned therein. I.e. when using a suture sleeve being adapted for two leads into a vein it is necessary to insert two leads. Otherwise, bleeding will occur. Accordingly, it is necessary to keep in stock suture sleeves adapted for one as well as for two leads to be prepared for different applications.
Moreover, the leads in question are very small, having a cross sectional dimension of only about 2 mm, which has to effect that also the suture sleeve will be very small. This will have to result that it will be very difficult to wrap around the leads properly with the suture sleeve, insert it through the opening in the vein and fixate the assembly by means of a suture thread without losing the suture sleeve during the handling. With a suture sleeve according to the aforementioned patent it is also impossible to completely eliminate bleeding since, as is evident from the drawings in the document, there will always remain some gaps between the leads and the suture sleeve in an assembled state.